The bug comes in one of two forms: Either you don't receive the email entirely, so you have no link to click on to claim your free Food, or, once you do try to claim it, you're given an error message, presumably from Frontier Jack, stating that he has no idea "what the heck you're trying to do."

Either way, this bug has come to Zynga's attention, as they have flagged it as a known issue on the Zynga customer support website. You can either help further bring the bug to Zynga's attention by filing another bug ticket yourself, or you can simply click on the "Vote" button on the issue's acknowledgement page to throw your hate into the ring if this is the bug you'd like Zynga to work on most, and first. Personally, there are a few other issues with the game that should probably be fixed before the Daily Energy Bonuses, but here's the option if you want it.